Impact of lateral cervical lymph node metastasis on lung metastasis in pediatric thyroid cancer: A correlation study

Background: Thyroid cancer (TC) frequently manifests with lung metastases in the pediatric population, occurring at a significant rate of 30 %. This study aims to evaluate the impact of regional patterns of cervical lymph node metastases on lung metastases in pediatric TC.Methods: Retrospective analysis was conducted on data from pediatric TC patients spanning the years 2000 to 2018. We compared the rates of lymph node metastasis (LNR), the number of lymph node metastases, and the number of dissected lymph nodes in the central and lateral cervical regions between patients with and without lung metastases. Statistical methods were employed to adjust for confounders during hypothesis testing.Results: A total of 227 pediatric patients, with a median age of 15.12 +/- 2.84 years, were included in the study. Of these, 202 (89 %) exhibited LN metastasis, with 40(17.62 %) patients presenting with lung metastasis. Patients with lung metastases were found to be younger (13.40 +/- 3.11 vs. 15.50 +/- 2.64, p <0.001), had larger primary tumor diameters (3.49 +/- 1.98 vs. 2.31 +/- 1.45, p <0.001), and exhibited a higher number of lymph node me-tastases (23.40 +/- 10.75 vs. 14.65 +/- 13.16, p <0.001). Notably, in patients with LN metastases, the presence of >12 lateral cervical lymph node metastases emerged as a significant risk factor for lung metastases. Among children with metachronous lung metastases, the median time to detection of lung metastases was 43 (12132) months, and they appeared to receive a greater proportion of radioactive iodine (RAI) treatment compared to those with synchronous lung metastases.Conclusion: Lateral cervical lymph node metastasis independently predicts the likelihood of lung metastases in pediatric TC. Furthermore, our findings emphasize the importance of thorough examination of the lungs during follow-up, particularly when the number of metastatic lateral cervical lymph nodes exceeds 12.